var one = document.getElementById('one');
	var two = document.getElementById('two');
	var oneList = one.getElementsByTagName('li');
	var twoList = two.getElementsByTagName('li');
	for (var i = 0; i < oneList.length; i++) {
		oneList[i].index = i;
		oneList[i].onmouseover = function() {
			clearInterval(timer);
			for (var j = 0; j < oneList.length; j++) {
				oneList[j].style.backgroundColor = 'orange';
			}
			this.style.backgroundColor = 'skyblue';
			for (var k = 0; k < twoList.length; k++) {
				if (k == this.index) {
					twoList[this.index].style.display = 'block';
				} else {
					twoList[k].style.display = 'none';
				}
			}
		}
		oneList[i].onmouseout = function() {
			a = this.index;
			timer = null;
			timer = setInterval(qiehuan, 2000);
		}
	}
	var timer = setInterval(qiehuan, 2000);
	var a = 0;

	function qiehuan() {
		for (var j = 0; j < oneList.length; j++) {
			oneList[j].style.backgroundColor = 'orange';
		}
		for (var i = 0; i < twoList.length; i++) {
			if (i == a) {
				twoList[a].style.display = 'block';
			} else {
				twoList[i].style.display = 'none';
			}
		}
		oneList[a].style.backgroundColor = 'skyblue';
		a++;
		if (a % oneList.length == 0) {
			a = 0;
		}
	}